21023677 has 2 divisors, whose sum is σ = 21023678. Its totient is φ = 21023676.

The previous prime is 21023663. The next prime is 21023699. The reversal of 21023677 is 77632012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13942756 + 7080921 = 3734^2 + 2661^2 .

It is a cyclic number.

It is not a de Polignac number, because 21023677 - 2¹¹ = 21021629 is a prime.

It is equal to p_1331389 and since 21023677 and 1331389 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21023077) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10511838 + 10511839.

It is an arithmetic number, because the mean of its divisors is an integer number (10511839).

Almost surely, 2^21023677 is an apocalyptic number.

It is an amenable number.

21023677 is a deficient number, since it is larger than the sum of its proper divisors (1).

21023677 is an equidigital number, since it uses as much as digits as its factorization.

21023677 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3528, while the sum is 28.

The square root of 21023677 is about 4585.1583396869. The cubic root of 21023677 is about 275.9960660715.

Adding to 21023677 its reverse (77632012), we get a palindrome (98655689).

The spelling of 21023677 in words is "twenty-one million, twenty-three thousand, six hundred seventy-seven".